Why would an object be deformed by subsurf and differ from the 3D view when rendered?
If you have a closer look at the modifier tab in the Properties Editor (you can find explanations of the terms I use in the documetnation) you will see that modifiers have these camera and eye icons. They define if the modifier is visible in the viewport(that includes rendered preview mode) and in the final render. This makes it possible to view less complicated scene in the viewport and therefore be able to interact with it without lag and then have a lot more detail in the rendered result that might not be interactive and smooth if viewed in the viewport while working. You have one modifier that is only visible in rendered result. If you do not want to have it, you should remove it completely by pressing the x icon in the right-most end of the icon row.